<!DOCTYPE html>

<html>

<head lang="en">
  <meta charset="UTF-8">
  <title></title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    table {
      border-collapse: collapse;
      border-spacing: 0;
      border: 1px solid #c0c0c0;
      width: 500px;
      margin: 100px auto;
      text-align: center;
    }

    th {
      background-color: #09c;
      font: bold 16px "微软雅黑";
      color: #fff;
      height: 24px;
    }

    td {
      border: 1px solid #d0d0d0;
      color: #404060;
      padding: 10px;
    }

    .allCheck {
      width: 80px;
    }
  </style>
</head>

<body>
  <table>
    <tr>
      <th class="allCheck">
        <input type="checkbox" name="" id="checkAll"> <span class="all">全选</span>
      </th>
      <th>商品</th>
      <th>商家</th>
      <th>价格</th>
    </tr>
    <tr>
      <td>
        <input type="checkbox" name="check" class="ck">
      </td>
      <td>小米手机</td>
      <td>小米</td>
      <td>￥1999</td>
    </tr>
    <tr>
      <td>
        <input type="checkbox" name="check" class="ck">
      </td>
      <td>小米净水器</td>
      <td>小米</td>
      <td>￥4999</td>
    </tr>
    <tr>
      <td>
        <input type="checkbox" name="check" class="ck">
      </td>
      <td>小米电视</td>
      <td>小米</td>
      <td>￥5999</td>
    </tr>
  </table>
  <script>
    // 获取全选框
    const checkAll = document.querySelector("#checkAll")
    // 获取所有剩余单选框
    const checkbox_arr = document.querySelectorAll(".ck")
    // 为全选框添加点击事件
    checkAll.addEventListener("click", function () {
      // 如果全选框被勾选中, 则每一个单选框都必须被选中,反之都取消选中
      for (let index = 0; index < checkbox_arr.length; index++) {
        checkbox_arr[index].checked = this.checked
      }
    })
    // 为剩余单选框添加点击事件
    for (let i = 0; i < checkbox_arr.length; i++) {
      checkbox_arr[i].addEventListener("click", function () {
        checkAll.checked = document.querySelectorAll(".ck:checked").length == checkbox_arr.length
      })
    }
  </script>
</body>

</html>